In this paper a comparative study of the impact of N 2 O and POCl 3 annealing on the SiO 2/SiC system is presented, combining nanoscale electrical characterization of SiC surface doping by scanning spreading resistance microscopy (SSRM) and scanning capacitance microscopy (SCM) to the conventional capacitance-voltage (CV) and current-voltage (IV) measurements on MOS-based devices. A significant reduction of the interface states density (from 1.8× 10 12 to 5.7× 10 11 cm-2 eV-1) and, correspondingly, an increase in the carrier mobility (from 19 to 108 cm 2 V-1 s-1) was found moving from N 2 O to POCl 3 annealing. Furthermore, SSRM measurements on bare p+-type SiC regions selectively exposed to N 2 O and POCl 3 at high temperature provided the direct demonstration of the incorporation of N or P-related donors in the SiC surface, leading to a partial compensation of substrate acceptors during N 2 …